diff --git a/src/data/floor_registry.ts b/src/data/floor_registry.ts
index 052cc34bd0..8bff8df5a3 100644
--- a/src/data/floor_registry.ts
+++ b/src/data/floor_registry.ts
@@ -76,7 +76,7 @@ export const floorCompare =
       const floorA = entries?.[a];
       const floorB = entries?.[b];
       if (floorA && floorB && floorA.level !== floorB.level) {
-        return (floorA.level ?? 9999) - (floorB.level ?? 9999);
+        return (floorB.level ?? -9999) - (floorA.level ?? -9999);
       }
       const nameA = floorA?.name ?? a;
       const nameB = floorB?.name ?? b;
diff --git a/test/data/floor_registry.test.ts b/test/data/floor_registry.test.ts
index 585247281b..abb14e89b0 100644
--- a/test/data/floor_registry.test.ts
+++ b/test/data/floor_registry.test.ts
@@ -26,7 +26,7 @@ describe("floorCompare", () => {
   });
 
   describe("floorCompare(entries)", () => {
-    it("sorts by level, then by name", () => {
+    it("sorts by level descending (highest to lowest), then by name", () => {
       const entries = {
         floor1: { name: "Ground Floor", level: 0 } as FloorRegistryEntry,
         floor2: { name: "First Floor", level: 1 } as FloorRegistryEntry,
@@ -35,13 +35,13 @@ describe("floorCompare", () => {
       const floors = ["floor1", "floor2", "floor3"];
 
       expect(floors.sort(floorCompare(entries))).toEqual([
-        "floor3",
-        "floor1",
         "floor2",
+        "floor1",
+        "floor3",
       ]);
     });
 
-    it("treats null level as 9999, placing it at the end", () => {
+    it("treats null level as -9999, placing it at the end", () => {
       const entries = {
         floor1: { name: "Ground Floor", level: 0 } as FloorRegistryEntry,
         floor2: { name: "First Floor", level: 1 } as FloorRegistryEntry,
@@ -50,8 +50,8 @@ describe("floorCompare", () => {
       const floors = ["floor2", "floor3", "floor1"];
 
       expect(floors.sort(floorCompare(entries))).toEqual([
-        "floor1",
         "floor2",
+        "floor1",
         "floor3",
       ]);
     });